Aziridines are three-membered ring nitrogen-heterocycles that are attractive substrates in the synthesis of pharmaceuticals and other products. For example, it has been proposed that aziridines be used in the preparation of oseltamivir (Tamiflu®).
Aziridines are attractive substrates in synthetic methodologies, in part, because of their potential as chiral synthons. In one such method, the aziridine is derived from a chiral precursor. In another, achiral meso-arizidines are ring-opened by chiral catalyst activation or are kinetically resolved via catalytic ring-opening. For example, Jacobsen et al., Org. Lett. 1999, 1, 1611-1613 reported the use of chiral chromium based catalysts in the ring-opening of aziridines with TMS-N3. Shibaski et al. later reported the use of catalysts derived from lanthanides provide good enantioselectivity for this desymmetrization strategy with both TMS-CN and TMS-N3 as nucleophiles. Using this approach, Shibaski et al., J. Am. Chem. Soc. 2006, 128, 6312-6313 synthesized oseltamivir. While such approaches provide certain advantages, they also employ metal-based catalysts with the attendant disadvantages.